On 7 Jun 2005 04:35:50 -0700, wrote:

My 2 cents on the subject of tuner loss.
A tuner will Always introduce more loss to the system.
If the total power output of the transmitter is not improved(ie, at
2:1 SWR), then using the tuner to reduce SWR to 1:1 is counter
productive, isn't it?

For me, not so. The manual for my Icom 735 says it is designed to
handle 1:1.5 swr, but to try to get it as close to 1:1 as possible.

I just tried an experiment on 20 meters with my 80 meter dipole and an
MFJ 989c tuner. At 1:1 swr, the meter measures 110 watts out; raising
the swr to 2:1 lowers the metered output to 20 watts. So I'm not sure
what the advantage of running a higher swr is.

bob
k5qwg


In other words, getting the SWR down to 1:1 from anything = 2:1, will
always cause a reduction in total power out.

Pat W0OPW

If you can't get the internal SWR meter on an Icom 735 (or similar
rigs) down to exactly 1:1 then either there's something wrong with the
tuner or with the tuner operator.

The tuner either works or it doesn't. There's no half-way house.
Without a tuner anything can happen. And it usually does.

There are far too many sleepless nights unnecessarily caused by the
SWR meter not being in the right imagined ballpark. Just ask
yourselves is the transmitter loaded with roughly 50 ohms or isn't it.
The SWR on the feedline hardly matters two hoots - the so called SWR
meter doesn't measure it anyway.

Do G5RV addicts realise that under even the best conditions the SWR on
the feedline is as high as 10-to-1 regardless of what the meter says.
But it doesn't seem to worry them.
----
Reg.

All my feedlines have a 9:1 SWR by design.

"Reg Edwards" wrote in message
...
If you can't get the internal SWR meter on an Icom 735 (or similar
rigs) down to exactly 1:1 then either there's something wrong with the
tuner or with the tuner operator.

The tuner either works or it doesn't. There's no half-way house.
Without a tuner anything can happen. And it usually does.

There are far too many sleepless nights unnecessarily caused by the
SWR meter not being in the right imagined ballpark. Just ask
yourselves is the transmitter loaded with roughly 50 ohms or isn't it.
The SWR on the feedline hardly matters two hoots - the so called SWR
meter doesn't measure it anyway.

Do G5RV addicts realise that under even the best conditions the SWR on
the feedline is as high as 10-to-1 regardless of what the meter says.
But it doesn't seem to worry them.
----
Reg.

Fred W4JLE wrote:
All my feedlines have a 9:1 SWR by design.

Heh, heh, I understand perfectly. Don't know
how many others do. :-) All my feedlines have
an SWR between 5:1 and 13:1 by design.
--
73, Cecil http://www.qsl.net/w5dxp

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I will be sending you some photos of my final installation. I did a number
of tests comparing how tight you can wind the loops. I was amazed at how non
critical it was, considering all the dire warnings one receives from the old
wife's tales.

Aside from all the ham bands, I have the need to get down to 3.347 MHz as
well. My setup with the thumbwheel digital rotary switches lets me look at
my chart, see 3.5 MHz needs 39 additional feet and set 39 in the switches,
I built a box outside the house with 4 dowel rods to wind the loops around.
It worked out great both mechanically and electrically.

After I inserted the relay box, I cut additional feedline off the 90 foot
feedline so the output side at the end of the coax agreed with the original
readings. Once that was accomplished all the plots were in agreement with
the predicted except on 40 meters. Predicted should have been 7.3, actual
was 6.8 MHz. Easy enough to correct for, but have not yet figured out what
causes it. All other freqs were spot on.

Worst SWR is 1.8:1 I am a happy camper. On 75 an A/B test shows no
difference was noted between it and a 75 meter dipole.

I need to A/B it on the other bands yet.

My method of 1,2,4,8 and 10,20,and 40 feet uses extra feed line, but is made
up for in the ability to enter feet directly on the switches.


Three other folks here are constructing a duplicate.

"Cecil Moore" wrote in message
...
Fred W4JLE wrote:
All my feedlines have a 9:1 SWR by design.

Heh, heh, I understand perfectly. Don't know
how many others do. :-) All my feedlines have
an SWR between 5:1 and 13:1 by design.
--
73, Cecil http://www.qsl.net/w5dxp

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Fred W4JLE wrote:
Once that was accomplished all the plots were in agreement with
the predicted except on 40 meters. Predicted should have been 7.3, actual
was 6.8 MHz. Easy enough to correct for, but have not yet figured out what
causes it. All other freqs were spot on.

What causes it is the feedpoint impedance of a one wavelength
dipole is very high and therefore easily upset by the surroundings.
A low impedance feedpoint impedance is not easily upset by the
surroundings. It's the same concept as using a 20k ohms/volt
voltmeter to measure the cathode voltage or the screen voltage
of a tube. One will give correct results and one won't.
--
73, Cecil http://www.qsl.net/w5dxp


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On Tue, 7 Jun 2005 14:45:32 -0400, "Fred W4JLE"
wrote:

I will be sending you some photos of my final installation. I did a number
of tests comparing how tight you can wind the loops. I was amazed at how non
critical it was, considering all the dire warnings one receives from the old
wife's tales.

Fred, any hints on winding your 450-ohm line around the wood dowels? I
have a feedline I wouldn't mind lengthening if I could do it without
loose ladderline everywhere.

bob
k5qwg

If you would send me an e-mail so I can get your address, I will send you
some photos. Are you on broadband or dial up?


"Bob Miller" wrote in message
...
On Tue, 7 Jun 2005 14:45:32 -0400, "Fred W4JLE"
wrote:

I will be sending you some photos of my final installation. I did a
number
of tests comparing how tight you can wind the loops. I was amazed at how
non
critical it was, considering all the dire warnings one receives from the
old
wife's tales.

Fred, any hints on winding your 450-ohm line around the wood dowels? I
have a feedline I wouldn't mind lengthening if I could do it without
loose ladderline everywhere.

bob
k5qwg

Bob Miller wrote:
Fred, any hints on winding your 450-ohm line around the wood dowels? I
have a feedline I wouldn't mind lengthening if I could do it without
loose ladderline everywhere.

You can string a straight piece of nylon/dacron rope from
one point to another and spiral the ladder-line using the
rope for support. Black tie wraps keep the ladder-line in
position. Another idea is to hang the ladder-line, accordion
style, under the eaves of your house.
--
73, Cecil http://www.qsl.net/w5dxp

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On Tue, 07 Jun 2005 12:22:05 -0500, Cecil Moore
wrote:

Fred W4JLE wrote:
All my feedlines have a 9:1 SWR by design.

Heh, heh, I understand perfectly.

You do?